CVE-2026-18431: Avada <= 7.16 and Fusion Builder <= 3.16 - Unauthenticated Remote Code Execution via Arbitrary File Write
The Avada theme for WordPress is vulnerable to Arbitrary File Write in all versions up to, and including, 7.16 when the Fusion Builder plugin is installed and active in versions up to, and including, 3.16. This is due to a chain of authorization and input validation weaknesses across the two components that makes it possible for unauthenticated attackers to write attacker-controlled files to the server. This can be used to create and execute arbitrary PHP files, resulting in remote code execution and complete site compromise. Successful exploitation requires both Avada and Fusion Builder to be installed and active, as well as certain administrator-authored content to be present.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Avada (WordPress theme)to a version that resolves this vulnerability.Fixed in 7.16 - Upgrade
Upgrade
Fusion Builder (WordPress plugin)to a version that resolves this vulnerability.Fixed in 3.16
Event History
Frequently Asked Questions
Which sites are exposed to exploitation?
A site is exposed only if it has both the Avada theme and the Fusion Builder plugin installed and active, at affected versions, and it contains the required administrator-authored content. The issue can be exploited remotely without authentication.
What access does an attacker need?
No account, privileges, or user interaction are required. An unauthenticated attacker can exploit the weakness chain to write attacker-controlled files and potentially execute PHP code on the server.
What is the likely impact of successful exploitation?
Successful exploitation can allow arbitrary PHP file creation and execution, leading to remote code execution and complete site compromise.